> ## Documentation Index
> Fetch the complete documentation index at: https://docs.0xarchive.io/llms.txt
> Use this file to discover all available pages before exploring further.

# Web3 Subscribe Schema

> Start Build or Pro access via x402 USDC payment JSON Schema contract. Includes route metadata, schemas, examples, and implementation notes.

Source OpenAPI: 0xArchive API 1.8.0; 227 paths; 217 component schemas.

x402-protected endpoint for purchasing 30-day Build or Pro access with USDC on Base. Unknown wallets receive an account and API key only after successful payment settlement. Existing disabled wallets are rejected before facilitator verification or settlement. **Flow:** 1. POST with `{ "tier": "build" }` (no payment header) → Server returns 402 with payment details (amount, pay\_to address, network) 2. Sign an EIP-712 `TransferWithAuthorization` (EIP-3009) on USDC Base for the specified amount 3. Build x402 v2 payment payload, base64-encode it, and retry with `payment-signature` header 4. Server verifies and settles payment via the facilitator → grants access → returns API key No API key required. Payment establishes paid wallet access.

## Route Metadata

| Field | Value |
| - | - |
| Method | `POST` |
| Path | `/v1/web3/subscribe` |
| operationId | `web3Subscribe` |
| Tag | Web3 Authentication |
| Family | Web3 Auth |
| Deprecated or legacy | no |

## Human endpoint reference

Open [`POST /v1/web3/subscribe`](/api-reference/web3-authentication/start-build-or-pro-access-via-x402-usdc-payment) for authentication, parameters, responses, and examples.

## Request Parameters

### Header Parameters

```json theme={"theme":"github-dark"}
{
  "$schema": "https://json-schema.org/draft/2020-12/schema",
  "title": "web3Subscribe header parameters",
  "type": "object",
  "properties": {
    "payment-signature": {
      "description": "Base64-encoded x402 v2 payment payload containing the EIP-3009 signed USDC transfer authorization. Omit on first request to receive payment details.",
      "type": "string",
      "x-parameter-location": "header"
    }
  }
}
```

## Request Body

### application/json

```json theme={"theme":"github-dark"}
{
  "$schema": "https://json-schema.org/draft/2020-12/schema",
  "title": "web3Subscribe request body",
  "type": "object",
  "required": [
    "tier"
  ],
  "properties": {
    "tier": {
      "description": "Subscription tier to purchase",
      "type": "string",
      "enum": [
        "build",
        "pro"
      ],
      "example": "build"
    }
  }
}
```

## Response Contracts

### Status 200

Subscription created successfully (returned when valid payment-signature header is provided)

#### application/json

```json theme={"theme":"github-dark"}
{
  "$schema": "https://json-schema.org/draft/2020-12/schema",
  "title": "web3Subscribe response 200",
  "type": "object",
  "properties": {
    "api_key": {
      "description": "The generated API key for the new subscription",
      "type": "string",
      "example": "0xa_..."
    },
    "expires_at": {
      "description": "Subscription expiration date (30 days from purchase)",
      "type": "string",
      "format": "date-time"
    },
    "tier": {
      "description": "The subscription tier activated",
      "type": "string",
      "example": "build"
    },
    "tx_hash": {
      "description": "On-chain transaction hash for the USDC transfer (if settled)",
      "type": "string",
      "nullable": true
    },
    "wallet_address": {
      "description": "The wallet address associated with the subscription",
      "type": "string"
    }
  }
}
```

### Status 402

Payment required. Response includes payment details: amount (micro-USDC), pay\_to address, and network. Sign and retry with payment-signature header.

#### application/json

```json theme={"theme":"github-dark"}
{
  "$schema": "https://json-schema.org/draft/2020-12/schema",
  "title": "web3Subscribe response 402",
  "type": "object",
  "properties": {
    "payment": {
      "type": "object",
      "properties": {
        "amount": {
          "description": "Amount in micro-USDC (6 decimals)",
          "type": "string",
          "example": "49000000"
        },
        "network": {
          "description": "Blockchain network",
          "type": "string",
          "example": "base"
        },
        "pay_to": {
          "description": "Treasury address to send USDC to",
          "type": "string",
          "example": "0x..."
        }
      }
    }
  }
}
```

### Status 403

The existing wallet account is disabled. No facilitator verification or settlement is attempted.

#### application/json

```json theme={"theme":"github-dark"}
{
  "$schema": "https://json-schema.org/draft/2020-12/schema",
  "title": "web3Subscribe response 403",
  "type": "object",
  "required": [
    "code",
    "error",
    "error_code",
    "request_id"
  ],
  "properties": {
    "code": {
      "type": "integer",
      "format": "int32"
    },
    "error": {
      "type": "string"
    },
    "error_code": {
      "type": "string"
    },
    "request_id": {
      "type": "string"
    }
  }
}
```

##### OpenAPI example

```json theme={"theme":"github-dark"}
{
  "code": 403,
  "error": "Account is disabled",
  "error_code": "account_disabled",
  "request_id": "00000000-0000-0000-0000-000000000000"
}
```

### Status 429

Rate limit exceeded

#### application/json

```json theme={"theme":"github-dark"}
{
  "$schema": "https://json-schema.org/draft/2020-12/schema",
  "title": "web3Subscribe response 429",
  "description": "Error response",
  "type": "object",
  "properties": {
    "code": {
      "description": "HTTP status code",
      "type": "integer"
    },
    "error": {
      "description": "Error message",
      "type": "string"
    },
    "error_code": {
      "description": "Machine-readable error code. Common values: `invalid_query_params` (a query parameter failed to parse or validate) and `invalid_path_params` (a path parameter failed to parse). Other endpoint-specific codes exist; treat unknown codes as generic errors of the given HTTP status.",
      "type": "string"
    },
    "param": {
      "description": "The parameter at fault, when the error is about one parameter.",
      "type": "string"
    },
    "request_id": {
      "description": "Unique request ID for support",
      "type": "string",
      "format": "uuid"
    },
    "success": {
      "description": "Always false on an error.",
      "type": "boolean",
      "example": false
    }
  }
}
```

##### OpenAPI example

```json theme={"theme":"github-dark"}
{
  "code": 429,
  "error": "Rate limit exceeded"
}
```


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